5 Marks Australian occupation, treasury note

Issued in the weeks following Australia's September 1914 seizure of German New Guinea, these notes were a field improvisation — the occupying forces needed a functional medium of exchange and had no time to wait for printed currency from home. Produced locally in Rabaul with whatever materials were at hand, they are among the most crudely manufactured emergency issues to emerge from the Pacific theatre of the First World War.

The entire series (Pick 1–5) is exceptionally rare. Most examples known to survive passed through very few hands before being preserved, which means heavily circulated pieces are actually harder to find than cleaner ones.